Pityriasis Lichenoides et Varioliformis Acuta, or Mucha Habermann's Disease, is a disease of the immune system. It is the milder version of Pityriasis lichenoides chronica. The disease is characterized by rashes and small lesions on the skin. It is not contagious and currently there is no cure for the disease, although the lesions can be treated with ultraviolet therapy.